Wave meter



Jung 2 1 1927 1,632,982 J. o. MAUBORGNE ET AL WAVE METER Filed Auz. 6. 1920 a-vwemtoc Lit) Patented June 21, 1927.

UNITED STATES PATENT OFFICE.

JOSEPH O. MAUBORGNE AND GUY HILL, OF WASHINGTON, DISTRICT OF COLUMBIA.

WAVE METER.

Application filed August 6, 1920. Serial N0. 401,746.

length or electric waves and alsov for trans initting from the \vavemeter radio signals oi? definite known frequencies for the purpose of calibrating other wzwemeters or radio receiving apparatus.

In its simplest form the wave coil is made in the form of a long helix, uniformly wound with suitable insulating wire closely spaced so that the inductance per unit length is relatively large.

\Ve have iouud'that it is desirable to wind the coil on a material having high insulatiug properties such as micarta, or bakelitedielectro. lWe get, therefore, in a comparalively short coil, the equivalent condition of a long line in the matter of wave development.

In the use of the wavemeter described in this specification for thepurpose of transmitting delinite wave lengths or frequencies, we make use of a wave coil of distributed inductance and capacity on which a wave development is produced by the transmitting source of the Wavemeter, the wavelength of the said wave development depending solely upon the electrical constants oil the coil and the position of the potential application to said coil, the wave coil by itself constituting the complete oscillatory system. The electro-magnetic Waves of the outgoing signals are emitted from each element of the wave coil, and we have here a condition where the electrical constants of the coil, the inductance, capacity, resistance and E. M. F. set up therein by excitation from a'suitable source of energy are all of a. distributed character and the energy is radiated from each element of the coil, mak ing it accordingly an ideal radiating system.

Similarly, using our invention as a receiving device -for the purpose of measuring the wavelength of a received radio signal, a

The resonance similar or the same wave coil is employed having distributed inductance and capacity of such magnitude as, to insure wave development along the coil for the frequencies of the signals we desire to receive and measure.

The electro-magnetic waves of the incom mg signals act uniformly on each element of the wave coil and we accordingly have a condition where the inductance, capacity, resistance of the coil, and the E. M. F. induced in it by the incoming signals are all of a distributed character making it in a sense an ideal wave conductor.

As a source of exciting our wavemeter for the purpose of transmitting signals of a definite frequency, we may make use of any or the methods described in our pending application Serial No. 389,450 covering the use of the wave coil as a transmitter. Likewise in using our wavemeter for the measurement of received signals we can make use'o't' the various methods of using the wave coil as a receiver, as described in our pending application, Serial No, 383,720.

As stated above, the fundamental princi ples underlying the use of the wave coil for the measurement of transmitted and received signals have been described atconsiderable length in our two pending applications re tel-red to above and therefore further explanation of these principles is considered unnecessary herein.

One of the main advantages that we claim for a wavemeter of the character herein described consists in the fact that the apparatus for measuring or determining the wave length consists of a single element,,which is a coil preferably in the form or a solenoid, as previously described, and which does'not' constitute a closed. circuit. By the use of such a wave coil no condenser is required. lVith .most existing forms of wavemeters which are capable of transmitting signals of a definite wavelength and with most forms of wavemeters which are used for measuring wavelengths ofreceived signals, the accuracy or the wavemeter depends to a large degree upon the accuracy of thecalibrat-ion of the variable or fixed condensers used in such waveineters. If a fixed condenser be used in a wavemeter, a variable in ductance has to be employed which also is subject to lack of permanency, thereby destroying the value or the wavemeter for ac curate measurements. a In our device asde scribed herein only one element, that re,

the Wave coil itself, is used to determine" W t and; he efore, f, his.v .11 be,

accurately constructed, there is only one e l ment that has to be kept in accurate adjustment and thereby the accuracy of the wavemeter is greatly increased.

In addition, as stated-above, this wave coil is. in no Way altered or the inductance or other? constants or 'the Wave coil varied in order to'inea'snfeoi: generate different Wave? hehsl we: mew do r t find a necessary to chan e the effective lei gth of the 'coils' In addition to the facts stated above, it is evident that increased caii jbe obtaind iniising ave coil for, difierent Wavelengths no change whatsoever isi'ina'de in the wave coil itself, aria-iii) artfof the wave coiliha s "to be: a1; ti ed, moived, or] listed in any, manner, j ei i l arise qf iwa l t ;rename by means ofinov n asnitab'le sham-fer slidfrs associated i eitherHectic-statically or In the use of the wave (3011 use Wave;

ele

met suit b humane" es e 80 cia'te f 'With lthe coil in order that wave} with the instrument. connectlo w th is Weveme er W m y flefiq i ti ivitlifit eem; nd'f e vf i ewii" q'jihef t" n. itsjsiinplest for'rnwenia f takea crystal def teeter" anc tel tdthesli'cler on the Wave coil, 1 T io nse WQXQ CQIl as a transmitt ng, vavenieter, e

' ay mii dyi a, ui a le i z er, new 2 make and, breakfoli'thelbuazer by a fi h, A w single ill 2$ l; l .d il eidiwd Col i e 'se ofoiir device as awavemae o hesfgbifiei a g Y- lt fi li ese y n' nle i el i sli a le "lifier in coi nectio with the waye co l acc irate 7 calibration o distanttrans};

s ations' ta be determined. Since a battery and conne t'eiaw one sid tli action" of the ave coil f or determining? 1130i weav ign ls. dep

he e finely,

tached any desired degree of amplification ca been; loyed, without effecting; the tan-*1 bretiqnb, the instrument in de re v y a stated above, in the useof this wave coil is ajtra f hel ave ete @1 the Qd l pendsu t en' the position of' application of'poterit'ialto ash fipjtwiei ajeai of high reg e 912 15 19 eceiver enefi i V the detector bya su table 's nglejlead me? over i e d amas: typ

e coil to which a single leadj'is .v., r, 1 l. Us, m t mawev m t rj h n th the coil. By changing tbepoint of application of the energy source to different positions along the coil, moving the slider on the coihal vays in the sa nedirection from to .the center, different Wavelengths are set up on the coil for each position of the applicationpoint and these are entirely independent of the construction or constants of the lead and-the associated circuits devised for supw' id in the for n oi. a long'helix. Itis to be n 'nderstood, however, that the invention is'in no Way limited to the use of awave coil of, this simple constrac'tio'n. desired, in order to get an extremely "long wayelength ona greatirange of Wave lengths in a given space, innltiole layer coils maybe employed.-

In addition, the Winding of the coilmay be banked on,one lialfior "closely ivonnd intlie foirn of, a lunip on one half and distributed or w oniid'witli' wider spacing on the other halfof the helix in order to obtain a very accurate ineasiirernent of a shorter range of; wavelengths over a comparatively long space t an;

Numerous other variations are evident, but it isi considerednnnecessary todescribe the as itflisconsidered that they are all merely modifications "of the pri'nciple of our invention whicliis to accurately determine wavelengths by; the rise of'a singlecalibrat ed coil used with associateda pamms Which does not redniiecalibration. By the use of our devi ejhowever, it is'nev ernecessary, in factit is undesirable, to c onne'ct the wave coil tol, the antenna systemor associated apparatns by an In'eans whatsoever or any transinitter offreceiver, the; 'tfreqr n'enc' or Wavelength offwhieli'is to be determined: Neither is it necessary to connect said-Wave 'llieprinciple of ogeration andthe metliod ofiising our "invention can'better be under-Q stood byreference to .theaccornpanying fdi- .agrarnniatic figures which show typical'em bo'di'rnentsio'f the invention and form "part of this specification]. In all of-tliefigiires herewith the same symbols and nonien'clatdre aregnsed to"designate"tlie' sarne app'a ratus and further reference to Various coinmon symbols will not be repeated except in cases where it is necessary to make clear the differences between the various figures.

In the accompanying drawings, Figure 1 is a diagrammatic View of the simplest form of the device as a practical wavemeter, embodying both the transmitting and receiving features;

Figure 2 shows a diagrammatic view of the wavemeter as the receiver, only, in which the vacuum tube detector or vacuum tube detector and amplifier are employed, as the detecting element; I

Figure 3 is similar to Figure 2 exceptthat a different type of slider is used on the wave coil;

Figure 4 is similar to Figure 3 except that there is introduced a neutralizing lead;

Figure 5 shows a modification as to the transmitting side of the wavemeter of the device when used for generating different wavelengths Figure 6 likewise shows in diagrammatic 3i rmanother modification of the wave meter used as a transmitter.

Having more particular reference to the drawings and to Figure 1, A represents the wave coil consisting of a helix ot suitablyinsulated wire, preferably copper closely wound in a single layer on an insulating tube. e prefer to make the length of the helix greater thanits diameter. B indicates the slider making direct contactwith the wave coil and capable otbeing moved along the wave coil. B is provided. with a pointer Y which moves over a graduated scale lV, showing directly the calibration on the coil in wavelengths or "frequencies. E represents the switch connected to B by a single lead. This switch, as shown in the figure, can either connect B to the receiving apparatus or to the transmitting apparatus of the wavemeter. lVhen this switch is thrown to contact 3, the wavemeter is adapted for the measurement of received signals. Contact 3 is connected to one side of a crystal detector Dfto the terminals 01 which detector are connected a pair of telephone receivers T. When the switch E is thrown on contact 4, the wave meter can be used to transmit waves oft predetermined length. Contact l. is connected to X, one side of the make and break of the buzzer Z as shown in the figure. The buzzer operates when the switch F is closed on contact 5 thereby completing the circuit of battery G, through the coils of the buzzer.

In the succeeding figures certain modificationsot the wavemeter as a transmitter and as a receiver are shown. The scale W and pointer Y are not repeated in the succeeding diagrams.

Figure 2 shows a modification of our wavemeter when used for the measurement of received signals at a considerable dis-- tance from the transmitter. By using suit able amplifier C, the connection shown in this figure enables the direct measurement of received signals to be obtained at a great distance from the transmitter. This Figure 2 is identical with FigureG of our application Serial Number 383,720. In this Figure A and B represent the coil and slider respectively similar to those shown in Figure 1. In this case the lead from the slider to the receiving device is indicated by the numeral 1. The lead, in the case of a vacuum tube detector, is always brought to the grid input terminal of the detector, or in the case of a multiple stage amplifier, to the input terminal or" the first stage oi the amplifier. Telephone receivers T in this diagram are plugged in at a suitable point in the circuit of the amplifier or detector C. The operation of the'wavemeter when employing connections as shown in Figure 2 is identical with the use of the wavemeter as a receiver, as described in our patent application Serial Number 383,720. In other words, the device referred to in our patent application Serial Number 383,720 just mentioned already constitutes a wavemet'er.

Figure 3 shows a diagrammatic view similar to Figure 2 in all respects except that slider B makes electro-st-atic connection with wave coil A instead of the direct connection made by slider B in Figure'2. This slider B may take any desired form such as an open or closed cylinder or an open or closed disc-of metal. Figure 3 is identical with Figure 1 of our patent application Serial Number 383,720. 7

Figure 4 is a diagrammatic view similar to Figure 3 except that a neutralizing-lead indicated on the figure by 2 twisted with lead 1 of Figure 3 so as to produce a twisted pair. (lne endv ot the neutralizing lead is attached to the filament, but the other end is left disconnected as shown in the drawing. The advantage of using the twisted pair of leads is that any radio energy which might be picked up by the lead from the slider to the grid input terminal of the amplifier is neutralized'by an equal amount of energy received by the filament lead. Hence no signal is produced in amplifier G due to the energy received by the leads. Under certain conditions this connection is of considerable advantage. Figure 4: of this specification is identical with Figure 2 of our patent application Serial Number 383,720.

Figure 5 is a diagrammatic view. showing a modification of the transmitting arrangement shown in Figure 1. A represents the wavecoil to which at point P- is connected, by any one of the methods described. a lead from a suitable source of undamped wave potential V, so designed as to produce at P on coil A a high'potential. This figwave coil.

m is identical with Fr re3of our enaing application Serial umber 389,450, de-

niitter. e V

*FigureG is a diagrammaticview showing anothermodification of the use of the Wave coil as a transmitter. This figure issimilar to'Fig'ure l exceptthat in place of utilia ing a buzzer as a source ofliigh potential to actuatethe wave coil A, a simpleinduction coil with a spark gap across its serondary terminals is employed. Thisfigiire is similar toFigui-el of our pending application Serial Number 389,450 describing the use of the Wave coil as atransinitter,

except that the interrupter of the induction coil is shown in slightly different form.

A probable explanation of the operation of our inventionwillhe understood from the following considerations:

The connection between the detector and the Wave coil is suchthat an impedance irregularity isintrodnced into the "wave coil tion particularly to the use of our device for r the purpose of measuring or generatiiig radio frequencies, it is to he understoodtliat the words radio frequencies are intended to cover frequenciesof approximately 5000 or above Whether employed for radio signaling' or for any other purpose and here it might be desired to determine ormeasure the Wave lengths or ,the frequencies employed.

It is also obvious, as five have stated above, that various changes and modifications may be made in the Wave coil and its .associated apparatus herein shown and described Without departing from the spirit of our invention or the scope of the following claims.

Claims:

scribing the use of a wave coil as a; trans-' 1. 111 an apparatus for measuring the length of electromagnetic waves the com bination of an open circuited and ungrounded resonance Wave coil calibrated along its length and capable of being acted upon" throughoutits entire length by the radiant energy from thetransmit-ting source Whose wave length is to be measured, an electron tube dctectorliaving grid, filamentand plate electrodes, aslidablemeznber on said resonance wave coil for establishing a capacity connection with the turns thereof, a connec-' tion between said member and the grid electro'de of said electron tube detector and a free ended connection wrapped around said aforementioned connection and connected to said filainentelectrode at oneend and'terminating short of said slidable member at the other end, said slidable member being arranged to locate on said resonance Wave coil the turn thereof Where themaximum potential is developed.

2. In an apparatus fordeceivin electromagnetic Waves the combination a? anopen circuited and ungrounded resonance jwave coil calibrated with respect to frequency along itslength and being electrically free at its opposite ends and capable of being acteduponthiougliout its entire length by f the radiant energy fronifa transmitting source, a detector, a responsive device connected with said detector, and means close 1y coupling said. detector with said resonance Wave coil. "I

3. In an apparatus for receivin electromagnetic Waves the combination oi anopen circuitcd and ungrounded resonance Wave coil calibrated Withrespect to frequency along its length and being electricallylree at itsopposite ends and capable of being acted iiip'on throughout itsv entire length by the m iant energy from a transmitting source, a detector, a responsive device con nected with said detector, and means immedlately ad acent and closely conforming Withthe contour of the turns of said wave ;coil for closely coupling said detector With saidwave coil.

J. O; MAUBORGNE 'GUY HILL; V 

